Disulfide Connectivity of Velaglucerase

Human beta-glucocerebrosidase


Human beta-glucocerebrosidase, also known as glucoceremidase, GCase, and velaglucerase, is an enzyme that is commonly found to be deficient in patients with Gaucher's disease. Currently, there are three drugs on the market to treat this disease. One being Genzyme's Cerezyme, Protalix's Taliglucerase and SHIRE's VPRIV.

The typical method used to sequence current biologics, as well as map post translational modifications, is a combination of proteolytic digestion followed by LC/MS. Unfortunately, sometimes this method is not enough for complete identification of some post translational modifications. I am interested in the oxidation of Cys residues for the formation of disulfide bonds.



Disulfide Structure
Human beta-glucocerebrosidase (GCase) has seven Cys residues, four of which make two disulfide bonds. These two disufide bonds are both located in the N-terminal region of the protein and separated by only one amino acid. One of my current projects is using mass spectrometry to discern the disulfide connectivity in regions of a protein that are rich with Cys residues.

GCase N-terminal residues 1-23: ARPCIPKSFGYSSVVCVCNATYCDS

Disulfide Connectivity: C4-C16 & C18-C23

Additional Resources
For additional information, see: Metabolic Disorders